The vector layer class by itself isn't very useful—it relies on other classes to do all the interesting work. Let's look at the source class,
ol.source.vector, and its subclasses first as it's the only thing that is absolutely needed to get a working vector layer.
The vector source class is named after its purpose—to be a source of vector features for a vector layer. It is responsible for fetching features when needed, providing them to the vector layer for rendering, and also for retrieving features based on various criteria. We won't actually use the vector source class as it is a base class for the classes we'll actually be using, such as
ol.source.GeoJSON in the preceding example. The following diagram shows how the vector source ...